Interlesion distance for radiofrequency pulmonary vein isolation: the quandary between targets and limits

Since the first description of the ‘CLOSE’ protocol for radiofrequency (RF) ablation for pulmonary vein isolation,1 its excellent efficacy and safety results have been replicated by several groups.2–4 The simplicity of targeting an inter-tag distance (ITD) of less than 6 mm without making it too prescriptive has facilitated the reproducibility of this protocol across several centres.4 In that light, we read with interest the paper by Hoffman et al. showing that targeting an ITD of 3–4 mm was superior to an ITD of 5–6 mm in improving first pass isolation (FPI) rates.5 The authors should be commended for their appraisal of the main limitation of this study: the premature termination in the absence of any signal for harm and the resulting small numbers. We would like to highlight a few further concerns. The premature termination of this study at just 42 patients was driven entirely by...